Timebanking software has always been much more centralised than LETS being produced by the national associations rather than the communities themselves. Thus all the timebanking platforms, sharing a unit of account have enjoyed a high degree of interoperability. The initial USA and UK systems were poorly built and managed and eventually both gave way to a free, well run, but closed source platform which now hosts several hundred timebanks. This means those timebanks are interoperable in theory but so far no policy exists to manage trading limits and no API to include software hosted elsewhere.